A guide-track transportation system using a guide-track vehicle has been attracting attention as a new transportation system. A vehicle that is adopted as this guide-track transportation system includes, for example, a collector provided on a side-surface part of the vehicle, and a guide wheel provided side by side with the collector. On a guide track on which a guide-track vehicle travels, a power rail for supplying electricity to the vehicle via the collector of the vehicle, and a guide rail that guides a travelling direction of the vehicle and abuts on the guide wheel of the vehicle are provided. A relative positional relationship between the power rail and the guide rail is necessary to correspond to a relative positional relationship between the collector and the guide wheel of the vehicle. That is, it is necessary to be in a positional relationship such that the power rail abuts on the collector and the guide wheel abuts on the guide rail. Therefore, when laying the guide track, a support unit and a construction method that are capable of managing the relative positional relationship between the power rail and the guide rail in high accuracy are required.
As such a support unit, an installation structure disclosed in Patent Document 1 is known. This installation structure has a structure in which an embedded plate is partly embedded in a side wall of a travelling track for the vehicle at substantially a right angle, an installation plate is tightened by a bolt on the embedded plate through an elongated hole formed in the embedded plate, and a guide rail is fixed on the installation plate by a clip. Furthermore, the installation structure has a structure in which an insulator-attached plate on which a power rail is attached via an insulator is tightened by the bolt on the installation plate through the elongated hole provided in the installation plate.